In the PAMELA method, highly radioactive fission products from the reprocessing of burned-out fuel elements are fused into boron silicate glass. The final product is a glass that is bottled in a cylindrical final storage container, also called an "ingot mold", made of stainless steel.
In a method proposed in U.S. Pat. No. 4,341,547, for the withdrawal of glass from a ceramic melting furnace using the suction method, one needs a suction tube about 1 m long that penetrates into the glass melt. This suction tube must be connected vacuum-tight to the final or ultimate storage container until the completion of the filling process. Before disposing of the filled final storage container, the suction tube must be removed, since the container is then sealed. For the removal of the suction tube there are basically only two possibilities:
1. The suction tube is separated mechanically from the final storage container after the latter is filled. The tube still partially filled with radioactive glass is treated as a secondary waste product, and disposed of separately from the storage container.
2. The whole suction tube is pushed into the final storage container filled with still-molten glass, after completion of the filling.